﻿using System;
using System.Collections.Generic;
using System.Text;
using System.Net.Security;
using System.Security.Cryptography.X509Certificates;
using System.Net;
using System.IO;


namespace MyHttpClient
{
    /// <summary>  
    /// 有关HTTP请求的辅助类  
    /// </summary>  
    public class HttpHelp
    {
        private static readonly string DefaultUserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; SV1; .NET CLR 1.1.4322; .NET CLR 2.0.50727)";
        /// <summary>  
        /// 创建GET方式的HTTP请求  
        /// </summary>  
        /// <param name="url">请求的URL</param>  
        /// <param name="timeout">请求的超时时间</param>  
        /// <param name="userAgent">请求的客户端浏览器信息，可以为空</param>  
        /// <param name="cookies">随同HTTP请求发送的Cookie信息，如果不需要身份验证可以为空</param>  
        /// <returns></returns>  
        public static HttpWebResponse CreateRequestHttpForGET(string url, int? timeout, string userAgent, CookieCollection cookies)
        {
            if (string.IsNullOrEmpty(url))
            {
                throw new ArgumentNullException("url");
            }
            HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
            request.Method = "GET";
            request.UserAgent = DefaultUserAgent;
            if (!string.IsNullOrEmpty(userAgent))
            {
                request.UserAgent = userAgent;
            }
            if (timeout.HasValue)
            {
                request.Timeout = timeout.Value;
            }
            if (cookies != null)
            {
                request.CookieContainer = new CookieContainer();
                request.CookieContainer.Add(cookies);
            }
            return request.GetResponse() as HttpWebResponse;
        }


        /// <summary>  
        /// 创建POST方式的HTTP请求  
        /// </summary>  
        /// <param name="url">请求的URL</param>  
        /// <param name="requestContent">随同请求POST的参数名称及参数值字典</param>  
        /// <param name="requestEncoding">发送HTTP请求时所用的编码</param>  
        /// <param name="contenType">发送HTTP请求时所用的请求头ContentType</param>  
        /// <param name="cookies">随同HTTP请求发送的Cookie信息，如果不需要身份验证可以为空</param>  
        /// <returns></returns>  
        public static string CreateRequestHttpForPOST(string url, string requestContent, Encoding requestEncoding, string contenType, CookieCollection cookies)
        {
            if (string.IsNullOrEmpty(url))
            {
                throw new ArgumentNullException("url");
            }
            if (requestEncoding == null)
            {
                throw new ArgumentNullException("requestEncoding");
            }
            HttpWebRequest request = null;
            //如果是发送HTTPS请求  
            if (url.StartsWith("https", StringComparison.OrdinalIgnoreCase))
            {
                ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(CheckValidationResult);
                request = WebRequest.Create(url) as HttpWebRequest;
                request.ProtocolVersion = HttpVersion.Version10;
            }
            else
            {
                request = WebRequest.Create(url) as HttpWebRequest;
            }
            request.Method = "POST";
            request.ContentType = contenType;

            if (cookies != null)
            {
                request.CookieContainer = new CookieContainer();
                request.CookieContainer.Add(cookies);
            }
            //发送body内容,json格式
            byte[] data = requestEncoding.GetBytes(requestContent);
            using (Stream stream = request.GetRequestStream())
            {
                stream.Write(data, 0, data.Length);
            }
            WebResponse response = request.GetResponse() as HttpWebResponse;

            using (StreamReader reader = new StreamReader(response.GetResponseStream(), requestEncoding))
            {
                return reader.ReadToEnd();
            }
        }

        private static bool CheckValidationResult(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors)
        {
            return true; //总是接受  
        }
    }
}